Hi Khonsort,
Thank You for using in Essential XlsIO.
We are sorry for the inconvenience caused. The issue reported by you has been fixed in our latest version. Could you please try upgrading to our latest version available for download from the below location.
http://www.syncfusion.com/downloads/latest-versionPlease try this and let us know if this helps.
Best Regards,
Vijesh.